1. Laser ablation-single-particle-inductively coupled plasma mass spectrometry as a multimodality bioimaging tool in nano-based omicsDino Metarapi, Johannes Teun van Elteren, Martin Šala, Katarina Vogel-Mikuš, Iztok Arčon, Vid Simon Šelih, Mitja Kolar, Samo B. Hočevar, 2021, izvirni znanstveni članek Opis: Advanced data processing and visualization techniques were applied to laser ablation-single particleinductively
coupled plasma mass spectrometry (LA-sp-ICPMS) data obtained from imaging of roots of
sunflower (Helianthus annuus L.) which were exposed to ionic silver (Ag+). Highly multiplexed images with
tissue level resolution were generated, showing the uptake and transformation of Ag+ to silver
nanoparticles (AgNPs) in whole root cross-sections, and revealing that the size of biosynthesized AgNPs is
predisposed by the reducing power of particular root compartments. Various Ag+ and AgNP visualization
strategies are shown with special emphasis on spatially resolved information associated with the number
and spherical-equivalent size of individual AgNPs in user-selected root cross-sectional regions, including
statistical analysis of the AgNP distribution. Normally, this multimodality information can only be obtained
by combining the results of techniques from several complementary platforms.
Ključne besede: Laser ablation, Ag XANES, bioimaging
Objavljeno v RUNG: 03.06.2021; Ogledov: 2913; Prenosov: 51
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2. Electrochemical dissolution of iridium and iridium oxide particles in acidic media : transmission electron microscopy, electrochemical flow cell coupled to inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy studyPrimož Jovanovič, Nejc Hodnik, Francisco Ruiz-Zepeda, Iztok Arčon, Barbara Jozinović, Milena Zorko, Marjan Bele, Martin Šala, Vid Simon Šelih, Samo B. Hočevar, Miran Gaberšček, 2017, izvirni znanstveni članek Opis: Iridium based particles as the most promising proton exchange membrane electrolyser electrocatalysts were investigated
by transmission electron microscopy (TEM), and by coupling of electrochemical flow cell (EFC) with online inductively
coupled plasma mass spectrometer (ICP-MS). Additionally, a thin-film rotating disc electrode (RDE), an identical location transmission
and scanning electron microscopy (IL-TEM and IL-SEM) as well as an X-ray absorption spectroscopy (XAS) studies have
been performed. Extremely sensitive online time-and potential-resolved electrochemical dissolution profiles revealed that iridium
particles dissolved already well below oxygen evolution reaction (OER) potentials, presumably induced by iridium surface oxidation
and reduction processes, also referred to as transient dissolution. Overall, thermally prepared rutile type IrO2 particles (T-IrO2)
are substantially more stable and less active in comparison to as prepared metallic (A-Ir) and electrochemically pretreated (E-Ir)
analogues. Interestingly, under OER relevant conditions E-Ir particles exhibit superior stability and activity owing to the altered
corrosion mechanism where the formation of unstable Ir(>IV) species is hindered. Due to the enhanced and lasting OER performance,
electrochemically pre-oxidized E-Ir particles may be considered as the electrocatalyst of choice for an improved low temperature
electrochemical hydrogen production device, namely a proton exchange membrane electrolyser.
Ključne besede: Iridium Oxide Par-ticles, Electrochemical Dissolution of Iridium, Ir L3-edge XANES
Objavljeno v RUNG: 23.08.2017; Ogledov: 4587; Prenosov: 0
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3. Atomically resolved dealloying of structurally ordered Pt nanoalloy as an oxygen reduction reaction electrocatalystAndraž Pavlišič, Primož Jovanovič, Vid Simon Šelih, Martin Šala, Marjan Bele, Goran Dražić, Iztok Arčon, Samo B. Hočevar, Anton Kokalj, Nejc Hodnik, Miran Gaberšček, izvirni znanstveni članek Opis: The positive effect of intermetallic ordering of platinum alloy nanoparticles on oxygen reduction reaction (ORR) activity has been well established. What is still missing is an understanding of selective leaching of the less noble metal from the ordered structure and its correlation to longterm ORR performance. Using a combination of kinetic Monte Carlo simulations and advanced characterization techniques, we provide unprecedented insight into dealloying of intermetallic PtCu3 nanoparticles a well-known binary alloy. Comparison of ordered and disordered samples with identical initial compositions and particle size distributions reveals an unexpected correlation: whereas the copper dealloying rates in the ordered and disordered counterparts are almost the same, in the ordered structure Pt atoms are surrounded by 15−30% more Cu atoms throughout all the stages of acid leaching. This more convenient Pt−Cu coordination explains the statistically significant increase of 23−37% in ORR activity of the ordered structure at all stages of alloy degradation.
Ključne besede: ORR activity, fuel cells, platinum alloy, nanoparticle stability, intermetallic ordering, kinetic Monte Carlo, dealloying, in situ ICP-MS
Objavljeno v RUNG: 27.09.2016; Ogledov: 6401; Prenosov: 0
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